Th Coast Guard’s Alaska Facebook page announced their discovery on Chenega Island in Prince William Sound at about 2:30 p.m., adding that the men were “safe aboard a Coast Guard helicopter.”

"After spotting their 20-foot vessel and a flag on the beach, the Jayhawk crew was able to land, embark the men, and safely transport them to Seward, Alaska, with no medical concerns," Coast Guardsmen wrote. "It was reported the men survived by eating kelp and drinking water while staying out of the elements in a cabin they found on the island."

The men had radioed a Friday report of engine troubles aboard their 20-foot jet boat during a return trip from Montague Island to Whittier. The Coast Guard previously said Monday that the search was ongoing, with efforts so far covering a total of 1,600 square miles and family members chartering a boat to help find the men.

The U.S. Coast Guard says three overdue Prince William Sound boaters survived until their Jan. 1, 2018 rescue on Chenega island at this cabin. (From USCG)

The Coast Guard issued a series of boating safety tips Monday night, urging mariners to monitor weather conditions on the National Oceanic and Atmospheric Administration's website and file a float plan with marinas, family and friends -- including a count of people aboard, destination and expected return time -- before leaving.

On the water, boaters should wear life jackets, carry marine flares and have a working marine-band radio. In addition, boaters should maintain operational bilge pumps make sure vessels are secured against heavy winds and rain.